| Edgar Robert Champlin | |
| Office: | 27th Mayor of Cambridge, Massachusetts |
| Term Start: | January 1899 |
| Term End: | January 1901 |
| Predecessor: | Alvin F. Sortwell |
| Successor: | David T. Dickinson |
| Office2: | Member of the Board of Aldermen of Cambridge, Massachusetts |
| Term Start2: | 1893 |
| Term End2: | 1893 |
| Office3: | Member of the Common Council of Cambridge, Massachusetts |
| Term Start3: | 1885 |
| Term End3: | 1887 |
| Party: | Republican |
| Birth Date: | November 9, 1858 |
| Death Date: | November 8, 1932 |
| Death Place: | Boston, Massachusetts |
| Alma Mater: | Harvard Law School, class of 1880 |
| Spouse: | Katherine E. Paine, m. December 12, 1883 |
Edgar Robert Champlin (November 9, 1858 – November 8, 1932) was a Massachusetts lawyer, banker, and politician who served as the twenty-seventh Mayor of Cambridge, Massachusetts.
Champlin attended Harvard Law School, graduating in June 1880. Champlin also read for the law in the law offices of Richard Henry Dana Jr. and Lewis S. Dabney.
Even before he graduated from Harvard Law School, Champlin was admitted to the bar, in April 1880.
Champlin married Katherine E. Paine of Cambridge on December 12, 1883.